/Engine/Source/Runtime/Core/Public/IO/IoDispatcher.h
If a reference database is provided, the IoStoreWriter implementation may elect to reuse compressed blocks from previous containers instead of recompressing input data. This must be set before any writes are appended.
void SetReferenceChunkDatabase ( [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [IIoStoreWriterReferenceChunkDatabase](API\Runtime\Core\IO\IIoStoreWriterReferenceChunkData-) > ReferenceChunkDatabase )